1. Field of the Invention
The invention relates to the field of analyzers or testers for testing circuits, particularly integrated circuits.
2. Prior Art
Analyzers and testers have been developed to test integrated circuits such as random-access memories (RAMs), read-only memories (ROMs), and other circuits which employ a plurality of separately packaged integrated circuits such as microcomputers. Logic analyzers have emerged for this purpose and are commercially available from a number of companies. For a general description of such analyzers, see "The Logic Analyzer: A Computer Troubleshooting Tool" by Robin, Computer Design, March 1976 beginning on page 89; Logic Analyzer Primer published by Tektronix, Inc., copyrighted 1976; and, The Logic Analyzer, Application Note 167-1 published by Hewlett-Packard, Inc. These analyzers most often store and display data, and unlike many other displays, they employ trigger pulses to terminate a particular sequence rather than for initiating the sequence.
Logic Analyzers may be employed to display input or output data bits, address bits, instruction bits, or the like. Multiple probes are used to couple the integrated circuit signal paths to the analyzer. If input data bits are to be displayed, these probes are connected to the appropriate pins of the integrated circuit package. If address bits are to be displayed, the probes are manually moved to the correct pins. Clip connectors, or the like, are not suitable for this application since the pin-signal configuration varies substantially from circuit-to-circuit. That is, by way of example, on one integrated circuit package the output data may be coupled to pins 1 through 8 of a dual in-line package, while on another memory the output data bits may be on other pins. Thus, the multiple probes must be manually moved for each of the circuits, or other lead changes must be made.
With the described improved analyzer, the pin-signal configuration of each circuit which is tested or analyzed is stored in a memory, referred to as a "personality table". A universal clip connector is used to interconnect the integrated circuit package with the analyzer. Selection means within the analyzer selects the appropriate signals from the connector based on the pin-signal data stored in the personality table. This eliminates the multiple probes often used in prior art analyzers.